Disproportionation of olefins

ABSTRACT

This invention relates to a process for disproportionation of hydrocarbon olefins by contacting said hydrocarbon at disproportionation conditions with a catalyst prepared by incorporating a metals solution containing cobalt, an element selected from the group consisting of molybdenum, tungsten and mixtures thereof, and a phosphorus-containing compound, into an alumina hydrogel.

FIELD OF THE INVENTION

This invention relates to a process for the disproportionation ofolefinic hydrocarbons utilizing a hydrogel-derived catalyst.

BACKGROUND OF THE INVENTION

Reactions of olefinic molecules in the presence of metalcontainingcatalysts to produce other olefinic molecules are known in the art as"disproportionation" reactions. A typical olefin disproportionationprocess is illustrated by U.S. Pat. No. 3,261,879, issued July 19, 1966,to Banks, wherein two similar non-symmetrical molecules of an olefinreact in the presence of certain catalysts to produce one olefin of ahigher carbon number and one olefin of a lower carbon number such as,for example, propylene disproportionation by the process of U.S. Pat.No. 3,261,879 to produce ethylene and butylenes.

A variation of this disproportionation process, which might be termed"reverse disproportionation", is illustrated by the Netherlands PatentApplication No. 6514985 of British Petroleum Company, Limited, publishedMay 20, 1966, wherein, in one modification, molecules of two dissimilarsymmetrical olefins are reacted to form two molecules of a single olefinproduct, e.g., ethylene and 2-butene react to form propylene.

Another variation of the process, being conveniently termed "ringopening disproportionation" to distinguish it from other variations, isdisclosed by British Patent Specification No. 1,163,657 of PhillipsPetroleum Company, published Sep. 10, 1969, wherein a cyclic olefin andan acyclic olefin react to form a single product molecule. For example,ethylene reacts with cyclopentene by ring opening disproportionation toproduce 1,6-heptadiene.

As used in this application, disproportionation process means theconversion of olefinic hydrocarbons into similar olefinic hydrocarbonsof higher and lower numbers of carbon atoms per molecule. Where thereactant comprises 1--or 2--olefins having relatively long chains, amixture of products is obtained comprising primarily olefins having botha larger and a smaller number of carbon atoms than the feed olefin butalso including other disproportionated products, for example, saturatedhydrocarbons, and other converted and unconverted material. Such anoperation is useful in many instances. For example, a more plentifulhydrocarbon can be converted to a less plentiful and therefore morevaluable hydrocarbon. One instance of such a conversion occurs when theprocess of this invention is used to convert both higher and lowermolecular weight olefins to olefins in the C_(IO) -C₁₆ range, a range ofolefins especially suitable for the manufacture of detergents. Anotherinstance of a disproportionation reaction having considerable value isthe disproportionation of propylene to produce ethylene and butene.

A variety of catalysts have been employed for conductingdisproportionation reactions, such as those disclosed in U.S. Pat. No.3,340,322, issued Sep. 5, 1967., U.S. Pat. No. 3,637,892, issued Jan.25, 1972; U.S. Pat. No. 3,760,026, issued Sep. 18, 1973., U.S. Pat. No.3,792,108, issued Feb. 12, 1974., U.S. Pat. No. 3,872,180, issued Mar.18, 1975., and British Patent Specification No. 1,128,091, publishedMar. 16, 1966.

The catalysts in the above references are generally prepared accordingto conventional methods such as impregnation, wherein a carrier isimpregnated with a solution of metals., co-precipitation, wherein acarrier compound and metals are simultaneously precipitated., orco-mulling, wherein dry powders are mixed with a suitable extrusion aidsuch as water and extruded.

A related case directed to the disproportionation of olefins using ahydrogel-derived catalyst is commonly-assigned copending applicationSer. No. 056,185, filed May 27, 1987, now U.S. Pat. No. 4,754,099.

SUMMARY OF THE INVENTION

The present invention relates to a process for the disproportionation ofolefinic hydrocarbons which comprises contacting said olefinichydrocarbons with a catalyst comprising cobalt, an element selected fromthe group consisting of molybdenum, tungsten and mixtures thereof, and aphosphorus-containing compound incorporated into an alumina hydrogelwhich is then processed to prepare the catalyst.

It has been found that a hydrogel-derived catalyst has improved activityin an olefin disproportionation process when compared to aconventionally prepared catalyst useful for disproportionation. Thehydrogel-derived catalyst in this invention can be prepared by addingcatalytically active metals to an alumina hydrogel as dry salts,solutions, or a mixture of dry salts and solutions. As used herein, theterm "salts" includes compounds and complexes. In an olefin productionprocess combining the steps of oligomerization, isomerization anddisproportionation such as that disclosed in U.S. Pat. No. 3,726,938,issued to Berger, it is preferred to use catalysts prepared according tothe instant invention in the disproportionation zone. Another advantageof the hydrogel route is a lower manufacturing cost due to reducedproduct yield loss and reduced number of heating steps. The catalystsprepared according to the invention have high surface areas, greaterthan about 225 m² /g, and substantial portions, greater than about 35%,of their pore volume in pores in pores having diameters less than about100 Å.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the process of the instant invention, the disproportionation of anolefinic hydrocarbon is accomplished by contacting the olefinichydrocarbon with a catalyst prepared by incorporating cobalt, an elementselected from the group consisting of molybdenum, tungsten and mixturesthereof, and a phosphorus-containing compound into an alumina hydrogeland subsequently processing the hydrogel to prepare the catalyst.

Olefins which are subjected to disproportionation according to theprocess of this invention include C₃ ⁺ olefinic hydrocarbons or C₃ ⁺internal olefins in combination with ethylene. A useful group of feedmaterials are olefinic hydrocarbons having carbon numbers ranging fromC₂ to about C₁₀₀ and mixtures thereof, preferably from C₂ to about C₆₀and mixtures thereof, and more preferably linear olefinic hydrocarbonshaving carbon numbers ranging from about C₄ to about C₄₀ and mixturesthereof. Examples of compounds most suitable for disproportionationaccording to this invention are acyclic 1- and 2- alkenes, and alkyl andaryl derivatives thereof having from 3 to 20 carbon atoms per molecule.Some specific examples of such olefins are propylene, 1-butene,2-butene, 1-pentene, 2-pentene, 1-hexene, 2-heptene, 1-octene, 2-nonene,1-dodecene, 2-tetradecene, 1-hexadecene, 2-methyl-1-butene,2-methyl-2-butene, 3-methyl-1-butene, 1-phenyl-2-butene, and 3-heptene.Higher disproportionation conversions and wider product distributionsare obtained at comparable reaction times with 1-olefins than with2-olefins. 3-olefins are disproportionated at still lower rates.

The feed should be essentially free of impurities which adversely affectthe reaction. A subsequent reactivation of the catalyst to remove theeffect of such impurities can be made repeatedly by heat treatment withair, using an inert gas to control burn-off temperature.

The catalyst of this invention is prepared by incorporating cobalt, anelement selected from the group consisting of molybdenum, tungsten andmixtures thereof, and a phosphorus-containing compound into an aluminahydrogel having a water content sufficient to provide a hydrogel whichis thixotropic, and subsequently calcining the hydrogel to prepare thecatalyst.

As used herein, the phrase "hydrogel which is thixotropic" refers to analumina hydrogel which becomes a fluid when it is subJected to anexternal force such as mixing, shaking, milling, shearing and the like.The amount of water which must be present in the hydrogel in order toobtain a hydrogel which is thixotopic can be readily determined by oneof ordinary skill in the art with a minimal amount of experimentation.In general, the hydrogel has a water content greater than about 70%,basis dry weight of alumina. In a preferred embodiment, the hydrogel hasa water content in the range of from about 70% to about 95%, preferablyfrom about 75% to about 90%, basis dry weight of alumina.

The catalysts used in this invention are prepared by the preparativetechniques disclosed in the following commonly-assigned, copendingapplications which are directed to hydrotreating: Serial No. 100,662,filed Sep. 24, 1987; Serial No. 100,663, filed Sep. 24, 1987 and SerialNo. 100,661, filed Sep. 24, 1987; and in the following U.S. patentsdirected to hydrotreating: U.S. Pat. No. 4,717,698, U.S. Pat. No.4,717,704 and U.S. Pat. No. 4,717,705, which are incorporated byreference herein.

The alumina hydrogel is typically prepared by titrating an aqueoussolution of one or more aluminum salt(s) with an appropriate acidic orbasic material or solution, optionally in the presence of aphosphorus-containing compound, to cause precipitation of the aluminagel. One skilled in the art will recognize that the alumina gel can beprepared by titrating an acidic aluminum salt such as, for example,aluminum sulfate, aluminum nitrate or aluminum chloride, in aqueoussolution with a basic precipitating medium such as, for example, sodiumhydroxide or ammonium hydroxide, optionally in the presence of aphosphorus-containing compound, or, by titrating an alkali metalaluminate such as, for example, sodium aluminate or potassium aluminate,in aqueous solution with an acidic precipitating medium such as, forexample, hydrochloric acid or nitric acid, optionally in the presence ofa phosphorus-containing compound. One skilled in the art will recognizethat the adjustment of the pH of an aluminum-containing solution tobetween about 5.5 and about 10.0 will result in precipitation of thealuminum as aluminum hydroxide or hydrated aluminum oxide.

As used herein, the term "a phosphorus-containing compound" is genericand refers to one phosphorus-containing compound as well as to more thanone phosphorus-containing compound. Suitable phosphorus-containingcompounds are the acids of phosphorus and their salts. Typical acids ofphosphorus include phosphonic acids, phosphinic acids, phosphorous acidsand the like. The phosphorus-containing compound is generally selectedfrom the group consisting of phosphoric acid, a phosphate salt andmixtures thereof. Suitable phosphate salts include alkali metalphosphates, alkali metal hydrogen phosphates, ammonium phosphate andammonium hydrogen phosphate. The phosphorus-containing compound ispreferably phosphoric acid and is preferably mixed with the acidaluminum species prior to the precipitation. Alternatively, thephosphorus-containing compound can be sodium or ammonium phosphate andmixed with the basic aluminum species prior to precipitation. Thephosphorus-containing compound can also be added as a separate solutionor added to both the acid aluminum species and the basic aluminumspecies without significantly affecting the results. Preferably, thephosphorus-containing compound is prepared using commercially available85% phosphoric acid although other phosphorus-containing materials maybe utilized. The amount of phosphorus-containing compound added to theacid aluminum species and/or the basic aluminum species is from about0.01 to about 0.60 moles of phosphorus per mole of aluminum.

In a preferred embodiment, the alumina hydrogel is prepared by titratingan aqueous solution of an alkali metal aluminate and an aqueous solutionof an acid aluminum salt to cause precipitation of the alumina gel.Suitable acidic aluminum salts include aluminum sulfate, aluminumnitrate and aluminum chloride. A preferred species is aluminum chloride.Suitable alkali metal aluminates are sodium aluminate and potassiumaluminate. The precipitation can be carried out by adding an aqueoussolution of the basic aluminum species to an aqueous solution of theacidic aluminum species or the procedure can be reversed by adding anaqueous solution of the acidic aluminum species to an aqueous solutionof the basic aluminum species (referred to as "sequentialprecipitation"). Preferably, the precipitation in the instant inventionis carried out by simultaneously adding the acid aluminum species andthe basic aluminum species to cause precipitation of the hydrogel(referred to as "simultaneous precipitation"). The maximum rate ofaddition of the acid aluminum species and the basic aluminum species isfixed by the rate at which the two streams can be mixed and the pH andtemperature of the system can be effectively controlled.

The ranges and limitations provided in the instant specification andclaims are those which are believed to particularly point out anddistinctly claim the instant invention. It is, however, understood thatother ranges and limitations that perform substantially the samefunction in substantially the same manner to obtain the same result areintended to be within the scope of the instant invention as defined bythe instant specification and claims.

The temperature and pH of the precipitation are important variables inthe preparation of the aluminas into which metals can be incorporated toform catalysts with desirable physical qualities. One skilled in the artwould recognize that changes in precipitation temperatures and pHsresult in changes in porosities. The optimal temperatures and pHs forthe precipitation of the aluminas can be determined with a minimalamount of routine experimentation. In the instant invention, aprecipitation temperature typically ranges from about 20° C. to about90° C., preferably from about 50° C. to about 85° C., more preferablyfrom about 55° C. to about 65° C., and a precipitation pH typicallyranges between about 5.5 and about 10.0, preferably between about 5.5and about 8.0, and more preferably between about 6.0 and about 7.5. Thelength of time required for the precipitation step is typically fromabout 15 minutes to about 45 minutes. The period of time for theprecipitation should be sufficiently long for adequate mixing of thematerials, but not long enough for enhanced particle growth to occur.

After the precipitation step is completed, the pH of the slurry isadJusted by the addition of the basic aluminate solution to fall in therange from about 8.0 to about 12.0, preferably about 9.0 to about 11.0,most preferably about 9.5 to about 10.5, and aged at a temperature inthe range from about 20° C. to about 90° C., preferably about 50° C. toabout 85° C. for at least 15 minutes. An upper limit on the length oftime for aging is not critical and is normally determined by economicalconsiderations. Aging times will typically range from about 0.1 to about10 hours, preferably from about 0.25 to about 5 hours, and morepreferably from about 0.25 to about 1 hour. In general, aluminas withacceptable properties are produced by holding the aging temperatureequal to the precipitation temperature.

After aging, the slurry is washed and filtered in routine fashion toremove substantially all of the water-soluble salts formed during theprecipitation of the hydrogel. The preferred solvent for washing iswater although other solvents such as lower alkanols may be utilized.

After washing, the metals are incorporated into the hydrogel. One methodfor adding the metals to the hydrogel is a reslurry step in which thehydrogel is reslurried with a metals solution containing solubilizedsalts of cobalt, an element selected from the group consisting ofmolybdenum, tungsten and mixtures thereof, and a phosphorus-containingcompound sufficient to deposit on the final catalyst from about 0.1%w toabout 5%w cobalt, from about 8%w to about 18%w molybdenum or about 10%wto about 32%w tungsten, and from about 0.5%w to about 6%w phosphorus.When mixtures of molybdenum and tungsten are utilized, the finalcatalyst contains from about 8%w to about 32%w molybdenum and tungsten.The solution may, however, contain amounts of cobalt and molybdenum ortungsten in excess of that required to deposit the aforesaid amounts ofmetals, which excess may be removed by washing or other techniquesfollowing the reslurry step. A typical metals solution can be preparedby combining a molybdenum solution with a cobalt solution. The metalssolution also contains a stabilizing amount of phosphorus. Typically,the metals solution contains an amount of phosphorus-containing compoundin the range from about 0.2 to about 4.5 moles of phosphorus per mole ofmolybdenum or tungsten. When a phosphorus-containing compound is addedto the acidic or basic species during precipitation of the hydrogel, theamount of phosphorus-containing compound added to the metals solution isadjusted to give a final calcined catalyst containing from about 0.5%wto about 6%w phosphorus. Suitable phosphorus-containing compounds arethe acids of phosphorus and their salts. Typical acids of phosphorusinclude phosphoric acids, phosphonic acids, phosphinic acids, phosphorusacids and the like. The phosphorus-containing compound is generallyselected from the group consisting of phosphoric acid, a phosphate saltand mixtures thereof. Suitable phosphate salts include alkali metalphosphates, alkali metal hydrogen phosphates, ammonium phosphate andammonium hydrogen phosphate.

The molybdenum solution consists of a water-soluble source of molybdenumoxide such as ammonium heptamolybdate or ammonium dimolybdate dissolvedin water and optionally, a phosphorus-containing compound. Hydrogenperoxide may also be used to aid in solution preparation in some cases.A preferred method for preparing the molybdenum solution consists ofadding hydrogen peroxide to the solution in an amount ranging from about0.1 to about 1.0 mole of hydrogen peroxide per mole of molybdenum.Optionally, a suitable soluble amine compound such as monoethanolamine,propanolamine or ethylenediamine may be added to the molybdenum solutionin order to aid in stabilization of the solution.

The tungsten solution typically consists of ammonium metatungstatedissolved in water and optionally, a phosphorus-containing compound. Apreferred method for preparing the tungsten solution consists of addinghydrogen peroxide to the solution in an amount ranging from about 0.1 toabout 1.0 mole of hydrogen peroxide per mole of tungsten. In addition, asuitable soluble amine compound such as monoethanolamine, propanolamineor ethylenediamine may be added to the tungsten solution in order to aidin stabilization of the solution.

The cobalt solution consists of cobalt salts dissolved in water andoptionally, a phosphorus-containing compound. A wide range of cobaltcompounds are suitable, such as cobalt nitrate, cobalt hydroxide, cobaltacetate, cobalt oxalate, or cobalt oxide. The preferred cobalt compoundis cobalt nitrate.

An alternative method for incorporating the metals into the hydrogel isto add dry, water-soluble metal salts of cobalt, a heavy metal selectedfrom the group consisting of molybdenum, tungsten and mixtures thereof,and a phosphorus-containing compound to the hydrogel and mix untildissolution and adsorption of the metal salts and thephosphorus-containing compound onto the gel is substantially complete.The metal salts of cobalt, molybdenum and/or tungsten andphosphorus-containing compound are added to the hydrogel in amountssufficient to incorporate into the final catalyst from about 0.1%w toabout 5%w cobalt, from about 8%w to about 18%w molybdenum or about 10%wto about 32%w tungsten and from about 0.5%w to about 6%w phosphorus.When mixtures of molybdenum and tungsten are utilized, the finalcatalyst contains about 8%w to about 32%w molybdenum and tungsten.

Molybdenum is generally added to the hydrogel as a dry, water-solublesource of molybdenum such as ammonium heptamolybdate or ammoniumdimolybdate. Tungsten is typically added to the hydrogel as ammoniummetatungstate. Cobalt is added to the hydrogel in the form of dry,water-soluble cobalt nitrate, cobalt hydroxide, cobalt acetate, cobaltoxalate or cobalt oxide, with cobalt nitrate being preferred. Thephosphorus-containing compound is typically added, either wet or dry, tothe hydrogel in an amount ranging from about 0.2 to about 4.5 moles ofphosphorus per mole of molybdenum or tungsten. Alternatively, thephosphorus-containing compound can be mixed with the dry cobalt salt orwith the dry molybdenum or tungsten salt prior to addition to thehydrogel. The phosphorus-containing compound is preferably added to thehydrogel as phosphoric acid, a phosphate salt and mixtures thereof.

A preferred method of mixing the dry metal salts of cobalt andmolybdenum and/or tungsten with the hydrogel consists of adding hydrogenperoxide to the mixture of dry metal salts and hydrogel in an amountranging from about 0.1 to about 1.0 mole of hydrogen peroxide per moleof molybdenum and/or tungsten. Optionally, a suitable amine compoundsuch a monoethanolamine, propanolamine or ethylenediamine may be addedto the mixture of dry metal salts and hydrogel in order to aid instabilization of the mixture of the metal salts and the hydrogel.

The dry metals salts of cobalt, molybdenum and/or tungsten and thephosphorus-containing compound (if added dry) are typically added to thehydrogel in the form of finely divided particles which are generally 100mesh or less in size. While particle size is not critical and largerparticle sizes may be utilized, it is economically advantageous to useparticles which are 100 mesh or less in size.

It is also within the scope of this invention to combine the two methodsdescribed above for adding the metals to the hydrogel. For example, onemetal may be added to the hydrogel as a dry salt and another added inthe form of a solution. Various permutations of this combination of drysalts additions and metals solutions additions would be obvious to oneskilled in the art.

The temperature and pH of the step in which the metals solutions and/orthe dry metal salts are mixed with the hydrogel are important variablesin the preparation of hydrogel-derived catalysts which have acceptabledensities and porosities. In general, higher temperatures yield lowerdensity catalysts. The pH of the mixing step, however, is critical tothe formation of catalysts having the desired properties. The mixing ofthe hydrogel support with the metals solution or the dry metal salts iscarried out at a pH in the range between about 4.0 and about 10.0,preferably between about 4.0 and about 8.0, and a temperature in therange between about 25° C. and about 100° C., preferably between about25° C. and about 80° C., until incorporation of the metals salts intothe gel is sufficient to yield a final calcined catalyst having fromabout 0.1%w to about 5%w cobalt, and from 8%w to about 32%w heavy metalselected from the group consisting of molybdenum, tungsten and mixturesthereof, and from about 0.5%w to about 6%w phosphorus. Typically, thetimes for mixing the hydrogel and the metals will range from about 0.5to about 2 hours. Optionally, the resulting material can be washed toremove unadsorbed metals and filtered in routine fashion.

Following the addition of the metals to the hydrogel, the resultingmaterial is processed in one of many routine methods to produce afinished catalyst. The material may be extruded and then dried andcalcined, dried, mulled with addition of water, extruded or pelletizedand calcined, or partially dried, extruded or pelleted, dried morecompletely and calcined. Drying is accomplished by conventional means.It may be carried out by forced draft drying, vacuum drying, air dryingor similar means. Drying temperatures are not critical and depend uponthe particular means utilized for drying. Drying temperatures willtypically range from about 50° C. to about 150° C.

In a preferred embodiment, the material is extruded and then dried.Alternatively, the material may be extruded after drying to the properloss on ignition (LOI). However, to facilitate extrusion, organicbinders and/or lubricants may be added prior to extrusion.

After drying, the material is calcined at a temperature in the range offrom about 500° C. to about 675° C., preferably from about 525° C. toabout 650° C., to produce the finished catalyst. The material may becalcined in an oxidizing or neutral atmosphere, although air ispreferred. However, if binders and/or lubricants are used the materialis heated in an oxygen-containing atmosphere, preferably air, in orderto burn out the binders and lubricants. Burn-out temperatures willdepend on the concentration of oxygen in the burn-out atmosphere as wellas the burn-out time involved. Typically, burn-out temperatures willrange from about 700° C. to about 900° C.

Certain other processing steps may be incorporated into theabove-described procedure without deviating from the scope and intent ofthis invention. For example, an intensive mixer-muller can be used toprocess the material prior to extrusion.

The final catalysts are found to have surface areas greater than about225 m² /g, pore volumes ranging from about 0.4 to about 1.2 cc/g andwith at least about 35% of its pore volume in pores having diametersless than about 100 Å. In general, the metals contents of the finalcatalysts range from about 0.1%w to about 5%w cobalt, preferably fromabout 0.1%w to about 4%w cobalt, from about 8%w to about 18%w,preferably from about 10%w to about 14%w molybdenum, or about 1O%w toabout 32%w, preferably from about 18%w to about 26%w tungsten, and fromabout 0.5%w to about 6%w, preferably from about 2%w to about 4%wphosphorus.

The process of the invention can be carried out either batchwise orcontinuously, using a fixed catalyst bed, or a stirrer equipped reactoror other mobile catalyst contacting process as well as any other wellknown contacting technique. Preferred reaction conditions, e.g.,temperature, pressure, flow rates, etc., vary somewhat depending uponthe specific catalyst composition, the particular feed olefin, desiredproducts, etc. The process is carried out at temperatures ranging fromabout 10° C. to about 350° C. and at pressures in the range of about 50psig to about 500 psig. The disproportionation reaction is usuallyeffected in a liquid phase in the presence of a small amount of ethyleneand if desired, liquid reaction diluents are utilized. Examples ofsuitable diluents are hydrocarbons free from aliphatic unsaturation,such as acyclic or alicyclic alkanes of from 6 to 12 carbon atoms, i.e.hexane, isooctane and cyclohexane. Also exemplary would be monoaromaticcompounds such as benzene and toluene. If the diluent is added, it ispresent in amounts up to 20 moles of diluent per mole of olefinicreactants.

The operable range of contact time for the process of this inventiondepends primarily upon the operating temperature and the activity of thecatalyst, which is influenced by surface area, promoter concentration,activation temperature, etc. In general, the distribution of products isnot drastically altered by variation in contact time. Shorter contacttimes are usually associated with higher temperatures, but, when largeramounts of higher molecular weight products are desired, a suitablecombination of contact time and temperature is selected. With properselection of conditions and contact times, very high efficiency ofconversion to desired products can be obtained.

In this application, space rates are given in WHSV (weight hourly spacevelocity., weight of reactant feed per weight of catalyst per hour).

With a fixed bed reactor, continuous flow operation at pressures in therange of about 50 psig to about 500 psig, preferably about 150 psig toabout 250 psig, with catalysts having densities ranging from about 0.5gram per cc to about 1.0 gram per cc and surface areas greater thanabout 225 m² /g, and at temperatures in the range of about 10° C. toabout 350° C., preferably about 100° C. to about 250° C., weight hourlyspace velocities in the range of about 0.1 to about 10.0 parts by weightof olefinic hydrocarbon feed per part by weight of catalyst per hour aresuitable. The space velocity is adjusted according to changes in densityof feed due to change of pressure or temperature, and variation inreaction temperature and the activity of the catalyst. The higher spacevelocities in general are associated with higher reaction temperatures.

The process of the instant invention will be further described below bythe following examples which are illustrative and which are not to beconstrued as limiting the invention.

ILLUSTRATIVE EMBODIMENTS Catalyst Preparation Catalyst A

99.3 kilograms of aluminum sulfate solution were prepared bysolubilizing 11.3 kilograms of gibbsite (alpha-alumina trihydrate, 34%LOI) in 88.0 kilograms of 27% sulfuric acid at a temperature slightlyabove 100° C. The solution was allowed to cool to 60° C. prior to use.77.1 kilograms of sodium aluminate solution were prepared bysolubilizing 28.3 kilograms of gibbsite (alpha-alumina trihydrate, 34%LOI) in 48.8 kilograms of 36% sodium hydroxide at a temperature slightlyabove 115° C. This solution was also allowed to cool to 60° C. prior touse. These two solutions were metered under computer control into aprecipitation vessel containing a deionized water heel (121.1 kilograms)held at 60° C., maintaining a constant pH of 7.3 and a temperature of60° C. The precipitation duration was fixed at 25 minutes. After theprecipitation step was complete excess sodium aluminate solution (8.1kilograms) was added to the slurry to raise the pH to the desired agingpH of 10.3. Total solution quantities used: acid--74.1 kilograms,base--51.0 kilograms. The slurry was aged for one hour at the elevatedpH. The slurry was then filtered in a single step on a 1'×10' horizontalbelt vacuum filter and washed with deionized water. The resultingalumina hydrogel generally had a water content between 75% and 90%,basis dry weight of alumina.

Into a vessel equipped with a high speed stirrer were added a portion ofalumina hydrogel prepared during a 25 minute precipitation (3500 g,81.0% LOI--665 g dry weight basis), water (86.0 g), cobalt nitratehexahydrate (193.3 g), 85% phosphoric acid (145.2 g) and ammoniumheptamolybdate (197.8 g). The mixture was stirred vigorously to"liquefy" the hydrogel. After reaction for 1.5 hours at 80° C. thecatalyst hydrogel slurry was passed through a Gaulin Model 15M LabHomogenizer using a pressure drop of 6000 psi. The stiffened materialfrom this homogenization step was extruded using a small, manifold andnozzle system designed in-house for the homogenizer system. Drying ofthe extrudate at 130° C. was followed by calcination at 525° C. for twohours. The properties of the catalyst are listed in Table I.

Catalyst B

Catalyst B was prepared in a manner similar to Catalyst A except thatthe preparation temperature was 21.5° C. and the final calcined catalystcontained 5.0% molybdenum. The properties of the catalyst are listed inTable I.

Catalyst C

99.3 kilograms of aluminum sulfate solution were prepared bysolubilizing 11.3 kilograms of gibbsite (alpha-alumina trihydrate, 34%LOI) in 88.0 kilograms of 27% sulfuric acid at a temperature slightlyabove 100° C. The solution was allowed to cool to 60° C. prior to use.77.1 kilograms of sodium aluminate solution were prepared bysolubilizing 28.3 kilograms of gibbsite (alpha-alumina trihydrate, 34%LOI) in 48.8 kilograms of 36% sodium hydroxide at a temperature slightlyabove 115° C. This solution was also allowed to cool to 60° C. prior touse. These two solutions were metered under computer control into aprecipitation vessel containing a deionized water heel (121.1 kilograms)held at 60° C., maintaining a constant pH of 7.3 and a temperature of60° C. The precipitation duration was fixed at 25 minutes. After theprecipitation step was complete excess sodium aluminate solution (8.1kilograms) was added to the slurry to raise the pH to the desired agingpH of 10.3. Total solution quantities used: acid--74.1 kilograms,base--51.0 kilograms. The slurry was aged for one hour at the elevatedpH. The slurry was then filtered in a single step on a 1'×10' horizontalbelt vacuum filter and washed with deionized water. The resultingalumina hydrogel generally had a water content between 75% and 90%,basis dry weight of alumina.

Into a vessel equipped with a high speed stirrer were added a portion ofalumina hydrogel prepared during a 25 minute precipitation (3500 g,81.0% LOI--665 g dry weight basis), cobalt nitrate hexahydrate (98.2 g),85% phosphoric acid (65.6 g) and ammonium heptamolybdate (178.6 g). Themixture was stirred vigorously to "liquefy" the hydrogel. After reactionfor 1.5 hours at 25° C. the catalyst hydrogel slurry was passed througha Gaulin Model 15M Lab Homogenizer using a pressure drop of 6000 psi.The stiffened material from this homogenization step was extruded usinga small, manifold and nozzle system designed in-house for thehomogenizer system. Drying of the extrudate at 130° C. was followed bycalcination at 600° C. for two hours. The properties of the catalyst arelisted in Table I.

Catalyst D

Catalyst D was prepared using a conventional dry pore volumeimpregnation technique. A solution suitable for impregnating 75 grams ofcalcined alumina support with a pore volume of 0.69 cc/g was prepared asfollows. An impregnation solution was made by combining 5.78 grams ofcobalt nitrate, 12.86 grams of ammonium dimolybdate and enough 24%aqueous ammonia to bring the solution to a total volume of 51milliliters. After adding the entire solution to the alumina support inseveral small portions with intermediate agitations, the impregnatedsupport was dried overnight at 150° C. and calcined in air for 2 hoursat 450° C. The properties of the catalyst are listed in Table I.

Catalyst Testing

Catalysts A, B, C and D were each tested utilizing the followingprocedure. For testing, 4 grams of undiluted catalyst sized 16-45 meshwere charged to a 0.60" ID stainless steel reactor equipped with a 0.19"OD thermowell. The catalyst was activated by heating in flowing air at arate of 50 cm³ /minute for 1.5 hours, while the temperature was rampedfrom ambient temperature to 975° F. The catalyst was held at 975° F for4 hours under flowing air, followed by flowing N₂ at 50 cm³ /minute foran additional 12 hours. After activation, the catalyst was cooled underN₂ to reaction temperature, 150° F, and equilibrium isomerized deceneswere introduced as feed.

Disproportionation rates were measured by monitoring the disappearanceof C₁₀ in the reaction product. The reaction temperature was heldconstant at 150° F for the 6.5 hour catalyst test, while feed weighthourly space velocity (WHSV) was adjusted twice during the run.Measurements of C₁₀ conversion were made after 1.5 hours at 32 WHSV, 2.0hours at 24 WHSV and 3 hours at 16 WHSV. The slope of the line obtainedfrom plotting C₁₀ remaining versus 1/WHSV then yielded the reactionrate. Disproportionation rates for the hydrogel catalysts are reportedrelative to the conventionally prepared impregnated catalyst (CatalystD). The results of the catalyst testing are presented in Table II.

As mentioned previously, hydrogel catalysts prepared by the process ofthe instant invention have improved disproportionation activitiesrelative to conventionally prepared catalysts. The disproportionationactivities in Table II are reported relative to Catalyst D, theconventionally prepared impregnated catalyst. Catalysts yieldingincreased higher disproportionation rates are shown by having valuesgreater than 1.00. It is evident from these data that hydrogel-derivedcatalysts, Catalyst A and Catalyst C, demonstrate enhanceddisproportionation rates on a volumetric basis relative to Catalyst D.It is also evident from these data that Catalyst B, which was notprepared according to the invention, has a disproportionation rate lowerthan the conventionally prepared impregnated catalyst.

                  TABLE I                                                         ______________________________________                                        Catalyst Properties                                                           Catalyst         A      B        C    D                                       ______________________________________                                        % wt. Molybdenum.sup.(a)                                                                       11.0   5.0      11.0 8.1                                     % wt. Cobalt.sup.(b)                                                                           4.0    4.0      2.25 3.2                                     % wt. Phosphorus.sup.(c)                                                                       4.0    4.0      2.0  0.0                                     Calcination Temperature                                                                        525    525      600  450                                     Surface Area.sup.(d) m.sup.2 /gm                                                               369    357      296  295                                     Pore Volume.sup.(e) cc/gm                                                                      0.85   0.65     0.53 0.51                                    Compacted Bulk Density.sup.(f)                                                                 0.36   0.61     0.71 0.66                                    gm/cc                                                                         Hg Pore Size Distribution.sup.(g)                                             <50 Å        8.1    25.7     9.1  4.7                                     50-70 Å      17.0   61.1     69.7 39.5                                    70-100 Å     13.4   7.2      17.7 33.3                                    100-150 Å    7.4    2.0      2.0  9.8                                     150-350 Å    9.4    2.3      1.5  7.5                                     >350 Å       44.7   1.7      0.0  5.2                                     ______________________________________                                         .sup.(a) Weight percent determined by neutron activation analysis or          atomic absorption spectroscopy.                                               .sup.(b) Weight percent determined by neutron activation analysis or          atomic absorption spectroscopy.                                               .sup.(c) Weight percent determined by neutron activation analysis or          atomic absorption spectroscopy.                                               .sup.(d) BET, by nitrogen adsorption/desorption, Micromeritics Digisorb       2500 Instrument.                                                              .sup.(e) By nitrogen adsorption, Micromeritics Digisorb 2500 Instrument.      .sup.(f) 209 cc volume fully settled in a graduated cup and weighed.          .sup.(g) Determined by mercury intrusion, to 60,000 psi using a               Micromeritics Autopore 9210, using a 130° contact angle and 0.473      N/m surface tension of mercury. Numbers listed are percent pore volume.       (a) Weight percent determined by neutron activation analysis or atomic     absorption spectroscopy. (b) Weight percent determined by neutron     activation analysis or atomic absorption spectroscopy. (c) Weight percent     determined by neutron activation analysis or atomic absorption     spectroscopy. (d) BET, by nitrogen adsorption/desorption, Micromeritics     Digisorb 2500 Instrument. (e) By nitrogen adsorption, Micromeritics     Digisorb 2500 Instrument. (f) 209 cc volume fully settled in a graduated     cup and weighed. (g) Determined by mercury intrusion, to 60,000 psi using     a Micromeritics Autopore 9210, using a 130° contact angle and 0.473     N/M surface tension of mercury. Numbers listed are percent pore volume.

                  TABLE II                                                        ______________________________________                                        Catalyst     A        B        C      D                                       ______________________________________                                        C.sub.10 Feed                                                                              Iso. C.sub.10                                                                          Iso. C.sub.10                                                                          Iso. C.sub.10                                                                        Iso. C.sub.10                           Reaction     150      150      150    150                                     Temperature, °F.                                                       Disproportionation                                                            Activity                                                                      Catalyst Weight, gm                                                                        4.0      4.0      4.0    4.0                                     Catalyst Volume, cc                                                                        11.5     6.6      5.5    5.1                                     Rate, g/g/hr 15.82    1.48     15.8   1.59                                    Relative Rate                                                                 Basis Volume 4.53     0.73     9.65   1.00                                    ______________________________________                                    

We claim:
 1. A process for the disproportionation of olefinichydrocarbons having carbon numbers ranging from C₂ to about C₁₀₀ whichcomprises contacting said olefinic hydrocarbons at disproportionationconditions with a catalyst prepared by a process which comprises:(a)preparing an alumina hydrogel having a sufficient water content toprovide a hydrogel which is thixotropic, (b) mixing said aluminahydrogel with cobalt, a heavy metal selected from the group consistingof molybdenum, tungsten and mixtures thereof, and aphosphorus-containing compound in an amount of from about 0.2 to about4.5 moles of phosphorus per mole of heavy metal at a pH in the rangebetween about 4.0 and about 10.0 and a temperature in the range betweenabout 25° C. and about 100° C. until adsorption of the cobalt, heavymetal and phosphorus-containing compound onto the gel is sufficient toyield a final catalyst having from about 0.1% by weight to about 5% byweight cobalt from about 8% by weight to about 32% by weight heavymetal, and from about 0.5% by weight to about 6% by weight phosphorus,(c) extruding the product of step (b), and (d) calcining the product ofstep (c) at a temperature in the range of from about 500° C. to about675° C.
 2. The process of claim 1 wherein said alumina hydrogel has awater content greater than about 70%, basis dry weight of alumina. 3.The process of claim 2 wherein said alumina hydrogel has a water contentin the range of from about 70% to about 95%, basis dry weight ofalumina.
 4. The process of claim wherein in step (a), aphosphorus-containing compound is added in an amount ranging from about0.01 to about 0.60 moles of phosphorus per mole of aluminum.
 5. Theprocess of claim 4 wherein said phosphorus-containing compound isselected from the group consisting of phosphoric acid, a phosphate saltand mixtures thereof.
 6. The process of claim 1 wherein said heavy metalis molybdenum.
 7. The process of claim 6 wherein said catalyst containsfrom about 0.1% by weight to about 4% by weight cobalt and from about 8%by weight to about 18% by weight molybdenum.
 8. The process of claim 1wherein said catalyst contains from about 2% by weight to about 4% byweight phosphorus.
 9. The process of claim 1 wherein saidphosphorus-containing compound is selected from the group consisting ofphosphoric acid, a phosphate salt and mixtures thereof.
 10. The processof claim 1 wherein the calcination is carried out at a temperature inthe range of from about 525° C. to about 650° C.
 11. The process ofclaim wherein said olefinic hydrocarbons have carbon numbers rangingfrom C₂ to about C₆₀ .
 12. The process of claim 1 wherein saiddisproportionation conditions include a temperature of from about 10° C.to about 350° C. and a pressure of from about 50 psig to about 500 psig.13. A process for the disproportionation of olefinic hydrocarbons havingcarbon numbers ranging from C₂ to about C₁₀₀ which comprises contactingsaid olefinic hydrocarbons at disproportionation conditions with acatalyst prepared by a process which comprises:(a) preparing an aluminahydrogel having a sufficient water content to provide a hydrogel whichis thixotropic, (b) mixing said alumina hydrogel with a solutioncontaining solubilized salts of cobalt, a heavy metal selected from thegroup consisting of molybdenum, tungsten and mixtures thereof and aphosphorus-containing compound in an amount of from about 0.2 to about4.5 moles of phosphorus per mole of heavy metal, at a pH in the rangebetween about 4.0 and about 10.0 and a temperature in the range betweenabout 25° C. and about 100° C. until adsorption of the cobalt, heavymetal and phosphorus-containing compound onto the gel is sufficient toyield a final catalyst having from about 0.1% by weight to about 5% byweight cobalt, from about 8% by weight to about 32% by weight heavymetal, and from about 0.5% by weight to about 6% by weight phosphorus,(c) extruding the product of step (b), and (d) calcining the product ofstep (c) at a temperature in the range of from about 500° C. to about675° C.
 14. The process of claim 13 wherein said alumina hydrogel has awater content greater than about 70%, basis dry weight of alumina. 15.The process of claim 14 wherein said alumina hydrogel has a watercontent in the range of from about 70% to about 95%, basis dry weight ofalumina.
 16. The process of claim 13 wherein in step (a), aphosphorus-containing compound is added in an amount ranging from about0.01 to about 0.60 moles of phosphorus per mole of aluminum.
 17. Theprocess of claim 16 wherein said phosphorus-containing compound isselected from the group consisting of phosphoric acid, a phosphate saltand mixtures thereof.
 18. The process of claim 13 wherein said heavymetal is molybdenum.
 19. The process of claim 18 wherein said catalystcontains from about 0.1% by weight to about 4% by weight cobalt and fromabout 5% by weight to about 18% by weight molybdenum.
 20. The process ofclaim 13 wherein said catalyst contains from about 2% by weight to about4% by weight phosphorus.
 21. The process of claim 13 wherein saidphosphorus-containing compound is selected from the group consisting ofphosphoric acid, a phosphate salt and mixtures thereof.
 22. The processof claim 13 wherein the calcination is carried out at a temperature inthe range of from about 525° C. to about 650° C.
 23. The process ofclaim 13 wherein said olefinic hydrocarbons have carbon numbers rangingfrom C₂ to about C₆₀.
 24. The process of claim 13 wherein saiddisproportionation conditions include a temperature of from about 10° C.to about 350° C. and a pressure of from about 50 psig to about 500 psig.25. A process for the disproportionation of olefinic hydrocarbons havingcarbon numbers ranging from C₂ to about C₁₀₀ which comprises contactingsaid olefinic hydrocarbons at disproportionation conditions with acatalyst prepared by a process which comprises:(a) preparing an aluminahydrogel having a sufficient water content to provide a hydrogel whichis thixotropic, (b) mixing said alumina hydrogel with dry, water-solublesalts of cobalt, a heavy metal selected from the group consisting ofmolybdenum, tungsten and mixtures thereof, and a phosphorus-containingcompound in an amount of from about 0.2 to about 4.5 moles of phosphorusper mole of heavy metal at a pH in the range between about 4.0 and about10.0 and a temperature in the range between about 25° C. and about 100°C. until adsorption of the cobalt, heavy metal and phosphorus-containingcompound onto the gel is sufficient to yield a final catalyst havingfrom about 0.1% by weight to about 5% by weight cobalt, from about 8% byweight to about 32% by weight heavy metal, and from about 0.5% by weightto about 6% by weight phosphorus, (c) extruding the product of step (b),and (d) calcining the product of step (c) at a temperature in the rangefrom about 500° C. to about 675° C.
 26. The process of claim 25 whereinsaid alumina hydrogel has a water content greater than about 70%, basisdry weight of alumina.
 27. The process of claim 26 wherein said aluminahydrogel has a water content in the range of from about 70%, basis dryweight of alumina.
 28. The process of claim 25 wherein in step (a), aphosphorus-containing compound is added in an amount ranging from about0.01 to about 0.60 moles of phosphorus per mole of aluminum.
 29. Theprocess of claim 28 wherein said phosphorus-containing compound isselected from the group consisting of phosphoric acid, a phosphate saltand mixtures thereof.
 30. The process of claim 25 wherein said heavymetal is molybdenum.
 31. The process of claim 30 wherein said catalystcontains from about 0.1% by weight to about 4% by weight cobalt and fromabout 10% by weight to about 18% by weight molybdenum.
 32. The processof claim 25 wherein said catalyst contains from about 2% by weight toabout 4% by weight phosphorus.
 33. The process of claim 25 wherein saidphosphorus-containing compound is selected from the group consisting ofphosphoric acid, a phosphate salt and mixtures thereof.
 34. The processof claim 25 wherein the calcination is carried out at a temperature inthe range of from about 525° C. to about 650° C.
 35. The process ofclaim 25 wherein said olefinic hydrocarbons have carbon numbers rangingfrom about C₂ to about C₆₀.
 36. The process of claim 25 wherein saiddisproportionation conditions include a temperature of from about 10° C.to about 350° C. and a pressure of from about 50 psig to about 500 psig.37. A process for the disproportionation of olefinic hydrocarbons havingcarbon numbers ranging from C₂ to about C₁₀₀ which comprises contactingsaid olefinic hydrocarbons at disproportionation conditions with acatalyst prepared by a process which comprises:(a) preparing an aluminahydrogel having a sufficient water content to provide a hydrogel whichis thixotropic, mixing a dry water-soluble salt of a heavy metalselected from the group consisting of molybdenum, tungsten and mixturesthereof, and a mixture of a dry, water=soluble cobalt salts and aphosphorus-containing compound in an amount of from about 0.2 to about4.5 moles of phosphorus per mole of heavy metal with said aluminahydrogel at a pH in the range between about 4.0 and about 10.0 and atemperature in the range between about 25° C. and about 100° C. untiladsorption of the heavy metal, cobalt and a phosphorus-containingcompound onto the gel is sufficient to yield a final catalyst havingfrom about 0.1% by weight to about 5% by weight cobalt, from about 8% byweight to about 32% by weight heavy metal, and from about 0.5% by weightto about 6% by weight phosphorus, (c) extruding the product of step (b),and (d) calcining the product of step (c) at a temperature in the rangefrom about 500° C. to about 675° C.
 38. The process of claim 37 whereinsaid alumina hydrogel has a water content greater than about 70%, basisdry weight of alumina.
 39. The process of claim 38 wherein said aluminahydrogel has a water content in the range of from about 70% to about95%, basis dry weight of alumina.
 40. The process of claim 37 whereinstep (a), a phosphorus-containing compound is added in an amount rangingfrom about 0.01 to about 0.60 moles of phosphorus per mole of aluminum.41. The process of claim 40 wherein said phosphorus-containing compoundis selected from the group consisting of phosphoric acid, a phosphatesalt and mixtures thereof.
 42. The process of claim 37 wherein said saltof said heavy metal is a molybdenum salt.
 43. The process of claim 42wherein said catalyst contains from about 0.1%w to about 4%w cobalt andfrom about 8%w to about 18%w molybdenum.
 44. The process of claim 37wherein said catalyst contains from about 2%w to about 4%w phosphorus.45. The process of claim 37 wherein said phosphorus-containing compoundis selected from the group consisting of phosphoric acid, a phosphatesalt and mixtures thereof.
 46. The process of claim 37 wherein thecalcination is carried out at a temperature in the range of from about525° C. to about 650° C.
 47. The process of claim 37 wherein saidolefinic hydrocarbons have carbon numbers ranging from C₂ to about C₆₀ .48. The process of claim 37 wherein said disproportionation conditionsinclude a temperature of from about 10° C. to about 350° C. and apressure of from about 50 psig to about 500 psig.